1. Field of the Invention
The present invention generally relates to a multi-tape measuring tool having a recoilable or retractable tape and at least one removable ruler-type tape stored in, and retractable from, a single housing. More specifically, the present invention relates to a multi-tape measure wherein at least one of the tapes is a tape removable from the measuring tool housing and imprinted with at least one architectural and/or engineering dimensional scale.
2. Description of the Prior Art
Conventional tape measures have been devised in a wide range of combinations. For example, U.S. Pat. No. 4,542,589 is directed to a tape measure and marker combination; U.S. Pat. No. 4,665,620 is directed to a tape measure and clip board combination; and U.S. Pat. No. 6,233,789 is directed to a tape measure and square tool combination. It is almost universal that the metal retractable tapes used in tape measures are marked with a 1:1 scale, so that the visual markings or indicia correspond to the actual dimension of the item being measured. Such markings or indicia can be in inches or centimeters, for example, or a combination of these, and can be divided to show eighths, sixteenths or thirty-seconds of an inch or hundreds and tenths of a centimeter. For this reason, most tape measures are not suitable for use with a civil or mechanical engineer's scale, or on an architect's scale. These scales are used, in contrast, to represent objects that are larger than those that can be drawn to their natural or complete size, and they are used to measure dimensions in a drawing or model in some proportional way. These scales are also used to determine the actual or full-size dimensions from drawings that have been so reduced in size.
Retractable metal tapes, which are permanently attached to the tape housing, are not suitable for use as scales for civil and mechanical engineers or architects. These metal tapes are basically two-dimensional and are typically printed only on one side of the tape—namely, the upper surface of the tape. This prevents but a limited amount of information to be printed, as only two sets of indicia are typically provided, one along each edge of the upper surface of the tape. However, the scales of civil engineer's scales typically show decimal parts with divisions of 10, 20, 30, 40, 60 and 80 to the inch, while the scales of mechanical engineers and architects typically use proportional feet and inches. The former is normally used for plotting, map-drawing and graphic solutions of problems, whereas the latter is used for machine and structural drawings.
Common scales include the following:
*Full size*Scale 6″ = 1′half-sized*Scale 4″ = 1′one-third sized*Scale 3″ = 1′quarter sized*Scale 2″ = 1′one-sixth sized*Scale 1½″ = 1′one-eighth sized*Scale 1″ = 1′one-twelfth sized*Scale ¾″ = 1′one-sixteenth sized*Scale ½″ = 1′one-twenty-fourth sized*Scale ⅜″ = 1′one-thirty-second sized*Scale ¼″ = 1′one-forty-eighth sized*Scale 3/16″ = 1′one-sixty-fourth sized*Scale ⅛″ = 1′one-ninety-sixth sized*Scale 1/16″ = 1′one-one-hundred-twenty-eighth sized
It is evident, therefore, that the extensive range of potential scales that are used by engineers and architects are too many to be shown or imprinted on a single surface of a retractable flat tape. For this reason, scales are frequently imprinted on an elongate rule having a triangular cross section, such configuration providing a total of six edges, and, therefore, six distinct scales can be imprinted or twelve scales if different scales are printed at opposing ends of the same edges. One disadvantage of this triangular form is that although it has more proportional scales on one rule than can generally be accommodated on flat rules such as retractable metal tapes, this is offset by the delay in finding the desired scale to be used and by the sheer bulkiness of the triangular configuration. Three flat scales are, therefore, equivalent to one triangular scale.
Many drafting professionals use a set of six or eight scales, each graduated in one division only. By having a complete set of scales, each to be read for only one frequently used proportional marking system, the engineer or architect can choose a simple rule in any given scale or in conjunction with any given drawing. As suggested, for plotting and map-drawing, the civil engineer scale may include decimals parts 10, 20, 30, 40, 50, 60, 80 and 100 to the inch. Such scales are typically not used for machine or structural work. This further multiplies the total number of scales that a professional might need in any given situation.
Traditional tape measures have not provided for these needs and, as noted, have on the whole only provided 1:1 scales on their flat surfaces. As most tape measures include only a single, two-dimensional or flat tape, the number of scales that can be imprinted thereon is necessarily extremely limited.
On the other hand, for some purposes a recoil-type or retractable tape measure, which may be bulky, may not work to advantage. For example, in a confined space such a tape measure may not be used because of its size. The user must then carry a separate, smaller ruler to make these measurements, although these small, lightweight rulers can easily be lost during a project.
Also known are measuring devices that include multiple tapes. See, for example, U.S. Pat. No. 6,223,446 which discloses a grade/level measuring device that includes a primary housing and a secondary casing, each of which contains like tape measuring blades. The device is intended to permit a user to make quick and accurate grade or height measurements with the two tape measure blades. However, both tapes appear to be similar in all respects, except that they are withdrawn from the tape measure along two different, generally orthogonal, directions. Neither tape is totally removable from the housing, and neither appears to bear engineering or architectural scales but only the conventional 1:1 scales.
Another patent, U.S. Pat. No. 5,815,940, discloses a take-out meter for attachment to conventional metal retractable tape permitting use of the tape measure with architectural/engineering drawing measurements, without the need for repetitive subtractions of fitting measurements. The objective of the design is to provide an attachment to a conventional and retractable measuring unit that permits a pipe fitter to make measurements quickly and easily. In U.S. Pat. No. 5,875,557, a scale is disclosed that is marked with centimeters and inches. The scale is 1:1. By lining certain scales on the tape, exact or actual or full linear measurements are permitted according to the metric system. At the same time, the approximate inch and foot linear determinations are permitted readily by sight. But since the scale is marked on a single side of a metal tape, only a limited number of scales can be accommodated. Frequently, however, engineers and architects use and require multiple scales when working with drawings drawn to different scales. The known tape measures do not provide them with the versatility or flexibility they derive from a sufficiently large set of scales that allows them to forego carrying a separate engineer's scale. It should also be noted that it is frequently inconvenient for a professional to use the retractable metallic tape, attached to the housing and having a cross-sectional curvature, in working with engineering drawings.
As can be seen, there is a need for an improved tape measure having not only the conventional recoilable or retractable tape, but also a smaller, removable ruler-type tape stored in a single, easily carried unit that provides the user with the flexibility of being able to use a wide range of scales he or she may require in addition to the conventional retractable tape.